Bed Chop

Modified FSJ Tech Area
Post Reply
User avatar

Topic author
Harry Dawg
Posts: 65
Joined: Tue Oct 12, 2021 3:59 pm
Location: Georgia
Contact:

Bed Chop

Post by Harry Dawg » Mon Jun 06, 2022 4:37 pm

Hello Folks.
Hope everyone had a good Monday.
The time has come for me to deal with my rusted out bed. The new fuel tank is on it's way from BJ'S and I need to finish it up.


The tail caps, a fender and one bit of the rear quarter panel need to be replaced. I have half a donor bed that I am planning on using for patch panels. I believe I am going to cut along the body seam to separate the tail caps from the main bed. At first I thought these were spot welded on there, but now I'm not so sure, so I think I'll just chop them off with the angle grinder and weld the new ones on.

Alternatively I was thinking about moving the cut further up into the main bed and going straight across. This way I can just butt weld the two parts together and not have to worry about lining up the tail caps and tail gate barell mounts.

I already burned the fender on there, and it came out pretty alright. If I could do it over I would weld it from the underside, but that's part of learning. I now need a die grinder to remake the body line as best I can where there was a seam. ImageImageImageImageImage

Sent from my Pixel 4a (5G) using Tapatalk

1969 J3000 - 1985 CJ7 - 1998 Grand Cherokee 5.9 Liter Limited - 2006 Grand Cherokee Limited
Rhino USA Brand Success Manager
South East Offroad Activist

User avatar

Topic author
Harry Dawg
Posts: 65
Joined: Tue Oct 12, 2021 3:59 pm
Location: Georgia
Contact:

Re: Bed Chop

Post by Harry Dawg » Mon Jun 06, 2022 4:47 pm

The worst of the rust is in the tail caps.Image

Sent from my Pixel 4a (5G) using Tapatalk

1969 J3000 - 1985 CJ7 - 1998 Grand Cherokee 5.9 Liter Limited - 2006 Grand Cherokee Limited
Rhino USA Brand Success Manager
South East Offroad Activist

User avatar

devildog80
Posts: 301
Joined: Wed Apr 13, 2022 2:41 pm
Location: Apache Junction AZ

Re: Bed Chop

Post by devildog80 » Tue Jun 07, 2022 12:13 pm

Following :)
1984 Grand Wagoneer, 401 ci (.030 over), A727 auto, Selec-trac NP229, AMC 20 REAR - D44 FRONT (6 LUG) WT 3.31, 4 in arch spring lift (not a woody - think it was ordered new without, 1984 the only year it was an option)
Rather be driving than waiting for modifications
Somebodys' bad answer, should prompt someone else to give the right answer, but no answer at all helps no one.


akguy09
Posts: 112
Joined: Mon Aug 30, 2021 6:11 am
Location: Ellicott, Colorado

Re: Bed Chop

Post by akguy09 » Tue Jun 07, 2022 1:45 pm

Best of luck to you. I hate the seams in the bed and I am getting rid of them in my bed as I fixed the rust holes, I filled the seams.
1979 Jeep J-10 304/T-18
2017 Jeep JK 2DR
2021 PowerWagon

User avatar

Topic author
Harry Dawg
Posts: 65
Joined: Tue Oct 12, 2021 3:59 pm
Location: Georgia
Contact:

Re: Bed Chop

Post by Harry Dawg » Tue Jun 07, 2022 1:48 pm

akguy09 wrote:Best of luck to you. I hate the seams in the bed and I am getting rid of them in my bed as I fixed the rust holes, I filled the seams.
That was my thought as well. Looks to me like an extra place for rust to form, as evidenced by my tail caps.
Would be interested to see some pics of your bed if you got any.

Sent from my Pixel 4a (5G) using Tapatalk

1969 J3000 - 1985 CJ7 - 1998 Grand Cherokee 5.9 Liter Limited - 2006 Grand Cherokee Limited
Rhino USA Brand Success Manager
South East Offroad Activist

User avatar

tgreese
Posts: 5474
Joined: Fri Jun 08, 2012 6:31 am
Location: Medford MA USA

Re: Bed Chop

Post by tgreese » Tue Jun 07, 2022 6:32 pm

The bed seam is two pieces of steel, above and below, bent 90 degrees and spot welded together. The '73-up beds have a space between the inner and outer bed sides behind the seams that holds debris and moisture. The dead space is there so any dents in the inner bed walls won't show through the outside of the bed. Filling the seams from the outside won't stop them from rusting through. My J10 has a series of plastic plugs along the inside bed sides that I presume was used to fill that area between the bed walls with cavity wax. I plan to do that to my J20 at some point ... The single-wall bed should not be as bad in this respect, though it still has the 90-degrees-bent edges of the top and bottom bed sides. Without treating the internal hidden edge of that bed seam, rust will still come from the inside and rust through the outside.
Last edited by tgreese on Wed Jun 08, 2022 10:25 am, edited 1 time in total.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 FCA Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.


akguy09
Posts: 112
Joined: Mon Aug 30, 2021 6:11 am
Location: Ellicott, Colorado

Re: Bed Chop

Post by akguy09 » Wed Jun 08, 2022 9:37 am

Good point, since mine were rusty, they got repaired, treated inside and welded together outside before being body worked
1979 Jeep J-10 304/T-18
2017 Jeep JK 2DR
2021 PowerWagon

User avatar

tgreese
Posts: 5474
Joined: Fri Jun 08, 2012 6:31 am
Location: Medford MA USA

Re: Bed Chop

Post by tgreese » Wed Jun 08, 2022 10:33 am

Corrected my [post above to specify that the double wall beds were used '73-up and they are worse in terms of rust.

I guess my main point is that the way the upper and lower panels are joined pretty much guarantees rust along that seam. Even if you weld the seams together from the outside, there will be water and air contacting raw steel through the seam opening on the inside. Not sure how it would have been built otherwise, but the design promotes rust. Any type of a flange between two body panels like that will rust.

I presume it's not as bad for newer cars that dunk the whole body in primer and use plated steel.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 FCA Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.

User avatar

Topic author
Harry Dawg
Posts: 65
Joined: Tue Oct 12, 2021 3:59 pm
Location: Georgia
Contact:

Re: Bed Chop

Post by Harry Dawg » Thu Jun 09, 2022 8:27 am

Thanks for your input Tgreese.

Sounds like I am lucky to have the single wall bed... And here I was thinking I had the rustiest J truck on the planet.
This rig will be living under a shed or garage from here on out, so I don't have too much concern on it rusting in the future.
Although the humid climate of Georgia may start to eat away at the seam regardless.
If it does, I reckon I will just fix it again!

Moving forward, would you suggest cutting along the bed seam with an angle grinder and cut off wheel, or try and remove the spot welds with the die grinder? I have a feeling the later will lead to a better job at the end, but I am an apprentice body worker at best and am having a hard time even locating the spot welds.

Thinking if I can just separate the tail caps from the main bed it will leave the 90 degree flange in tact.
This way I have something to weld the new tail caps on to from the back side.
1969 J3000 - 1985 CJ7 - 1998 Grand Cherokee 5.9 Liter Limited - 2006 Grand Cherokee Limited
Rhino USA Brand Success Manager
South East Offroad Activist


Glad the Impaler
Posts: 36
Joined: Sun Mar 28, 2021 10:37 pm

Re: Bed Chop

Post by Glad the Impaler » Thu Jun 09, 2022 8:55 am

For what it's worth - here's my post on bobbing my single wall 8ft bed to a 7ft bed (primarily for offroading benefits).

My bed was in pretty good condition - so the reason for bobbing was not rust related at all.

https://www.fsjnetwork.com/forum/viewto ... 40#p209889

User avatar

Topic author
Harry Dawg
Posts: 65
Joined: Tue Oct 12, 2021 3:59 pm
Location: Georgia
Contact:

Re: Bed Chop

Post by Harry Dawg » Fri Jun 10, 2022 11:20 am

Hey Glad the Impaler.
Thanks for the info. I have been following your build for some time now, but I didn't realize you had about finished it up!
Looking great by the way. Admirable fab work, and the craftsmanship is outstanding.
I was thinking about bobbing mine, but I just couldn't bring myself to chop the frame.
If departure angle ends up being too much of an issue I might consider this, but for right now I am just going to run a heavy bumper and if I drag so be it.
I do think I might end up with a cleaner bed if I just cut it straight across like you did. Then it will just be one weld versus 3.
1969 J3000 - 1985 CJ7 - 1998 Grand Cherokee 5.9 Liter Limited - 2006 Grand Cherokee Limited
Rhino USA Brand Success Manager
South East Offroad Activist

User avatar

Topic author
Harry Dawg
Posts: 65
Joined: Tue Oct 12, 2021 3:59 pm
Location: Georgia
Contact:

Re: Bed Chop

Post by Harry Dawg » Thu Jun 23, 2022 7:22 am

Howdy Y'all.
Hope everyone has been doing well this past week.
It's been hotter than 2 rats fornicating in a wool sock here in GA, so progress has been slow.

I have gotten the rusted tail caps off of the bed, and have some somewhat clean metal to work with.
I tried a variety of methods including; grinding the spot welds with the a die grinder, punching the spot welds out with a spot weld remover drill bit and cutting the spot welds with an angle grinder and cut off wheel.

I found that the best and easiest way to get them off was to use the drill bit. It is quick, quiet and leaves the panel relatively intact.
This does have it's limitations though, as this method only works on easily accesible spot welds that you can get a drill into.

For the inner bed seam, I ended up cutting between the two panels with an angle grinder.
At first I was hitting the spot welds with a die grinder, but being inside the bed wall this just made for a PITA.
Also it would direct the hot sparks and shavings right back at me off the bed wall, and with the heat index being 108 I tired of this very quickly.

Anyways, here are some photos of the current progress. Currently in the process of removing the patch panels from the donor bed.

I also got the fender patch 70% finished. Just need to fill in some pin holes and blend the welded seam a little better.
1969 J3000 - 1985 CJ7 - 1998 Grand Cherokee 5.9 Liter Limited - 2006 Grand Cherokee Limited
Rhino USA Brand Success Manager
South East Offroad Activist

User avatar

Topic author
Harry Dawg
Posts: 65
Joined: Tue Oct 12, 2021 3:59 pm
Location: Georgia
Contact:

Re: Bed Chop

Post by Harry Dawg » Thu Jun 23, 2022 7:24 am

Bed picsImageImageImageImageImageImage

Sent from my Pixel 4a (5G) using Tapatalk

1969 J3000 - 1985 CJ7 - 1998 Grand Cherokee 5.9 Liter Limited - 2006 Grand Cherokee Limited
Rhino USA Brand Success Manager
South East Offroad Activist

User avatar

Topic author
Harry Dawg
Posts: 65
Joined: Tue Oct 12, 2021 3:59 pm
Location: Georgia
Contact:

Re: Bed Chop

Post by Harry Dawg » Thu Jun 23, 2022 7:31 am

Tools usedImage

Sent from my Pixel 4a (5G) using Tapatalk

1969 J3000 - 1985 CJ7 - 1998 Grand Cherokee 5.9 Liter Limited - 2006 Grand Cherokee Limited
Rhino USA Brand Success Manager
South East Offroad Activist

Post Reply

Who is online

Users browsing this forum: Bing [Bot], JWestfall and 1 guest